The suit, filed by a coalition of environmental groups, sought to overrule the Obama administration's refusal to declare 1.3 million acres as critical habitat for the panther, Florida's state animal.

Although panthers have been on the federal endangered list since 1967, the U.S. Fish and Wildlife Service has not declared any of its habitat to be critical, a step that would make it harder for developers, miners and farmers to alter the land.

The agency has repeatedly rejected petitions to declare any land occupied by panthers to be critical to the species' future survival. Not even a letter signed by three Florida members of Congress could change the agency's decision.

In 2002, a group of panther and habitat mapping experts who were convened by the Fish and Wildlife Service recommended the federal agency declare the area where the panthers now live as critical habitat. Protecting the 1.3 million acre "primary zone" would ensure the species' survival, they said. But the agency did not follow that recommendation.

The federal wildlife agency has not formally objected to any development in panther habitat since 1993.

However, it recently initiated a program to work with major South Florida landowners to set aside habitat in some areas while allowing development in others, an approach backed by Audubon of Florida, Defenders of Wildlife and the Florida Wildlife Federation but criticized by other environmental and civic groups.

Last year, the critics — the national Sierra Club, the Center for Biological Diversity, the Conservancy of Southwest Florida and the Council of Neighborhood Civic Associations —filed suit in federal court in Fort Myers over those repeated rejections of critical habitat.

The problem is, the panther was put on the endangered list prior to 1978 — the year when Congress changed the Endangered Species Act to require the interior secretary to designate critical habitat for any species added to the endangered list.

For a species like the panther, U.S. District Judge John E. Steele pointed out in his 28-page ruling, the law "allows the secretary to declare critical habitat for such endangered species, but does not require it."

The judge said that means it's entirely up to the Fish and Wildlife Service to decide how to protect panther habitat.

Michael Robinson of the Center for Biological Diversity said the groups were disappointed but believe "there is ample grounds for appeal." Officials from the Fish and Wildlife Service could not be reached for comment.